Libre Fermi (リブレ・フエルミ) was one of leaders of Demi-Human Alliance during the Demi-Human War.
Being active in only one novel–Ex2 spinoff novel–Libre played a rather important role, serving as one of the three commanders of the Demi-Human Alliance, and, following the death of Pivot Arnancy, he played a pivotal role in Bordeaux Zelgeff's character development, being directly responsible for his personality change.
Libre was a Snake Human and had a long body with green scales and yellow eyes. He wore a Jiangshi hat and had a black and purple Kararagi uniform with red ribbons.
As the moral heart and centre of Demi-human Alliance, Libre was one of its most influential leaders. Intelligent and perspective, he occupied the middle ground in his views for the purpose of war compared to Valga and Sphinx. For him, it was the means to bring the Kingdom to the negotiation table for the future of all the Demi-Humans, and not for destruction of humans or making use of them in experiments. He detested unnecessary violence or desecration of dead humans and Demi-Humans alike, for use in war.
As one of the leaders of the Demi-human Alliance, Libre fought side by side with Valga & Sphinx under a shared purpose. However, as the war raged on over the years, Valga started to change, to which in response Libre began grow estranged from him especially over Sphinx, whose methods had started becoming increasingly questionable despite the giant's support. This growing discontent would eventually come to head at the Battle of Aihiya Swamp, where Libre would ambush the Zegrv Squadron and slaughter many of its members including Pivot Arnancy. Although just barely coming out of the effects of large-scale magic that covered the battlefield, Wilhlem would duel him and after some intense combat, Libre would claim the upper hand. However before he could deliver the killing blow, Sphinx would show up unexpectedly and showered him with Jiwald spells, murdering him in order to raise the snake-human from the dead as a Corpse Solider to cover her escape much to his rage and humiliation at the betrayal.
In the Battle for the Royal Castle, Libre, now undead and under Sphinx's control, would fight against Wilhelm and company once more. He battled Bordeaux Zellgef until the spell over him was broken due to Sphinx suffering a severe amount of damage. As his last act as himself before turning into ash, he chopped off Sphinx's remaining arm in revenge, before dying–this time for good.
Doubled-Blade Fighting-Style: Wielding fierce and tricky combat-style with his double-blade sword, Libre was a terrible and overwhelming foe on the battlefield. He possessed enough skill that he was capable of defeating even Wilhelm, marking him as one of Sword Demon greatest challenges in the Civil War.
Regeneration: Libre was able to regenerate lost limbs due to his ancestral blood being from the Serpent Tribe.
Poison: Libre was able to poison his targets.
Equipment: Libre wielded a sword with both blades at both ends of the hilt. He was extremely profficient with it, and was even able to overpower young Wilhelm. He would have easily killed him, if it wasn't for Sphinx appearing out of thin air and slaughtering him in order to resurrect him and cover her retreat.
- Libre means free in both Spanish and French.